<section>
  <fui-upload
    [fileTypes]="['text/plain']"
    [showUploadTip]="false"
    (uploadFileChange)="onUploadFileChange($event)"
    fileTypesErrorText="文件格式错误"
  >
  <button fuiBtn="primary" [fuiBtnLoading]="loading" [disabled]="loading" > upload </button>
  </fui-upload>
  <p>只支持.txt</p>
  <div class="file-content">
    Text file content:  
    <p>{{ fileContent }}</p>
  </div>
</section>